2003 Lincoln Navigator

The second leg of the Santa-Barbara trip had us behind the wheel of the 2003 Lincoln Navigator.

The second leg of the Santa-Barbara trip had us behind the wheel of the . The'03 Navigator carries a four-wheel independent suspension, rack-and-pinion steering, and a new frame.

For comparison, we had back-to-back driving time in a competitor's top-of-the-line SUV and theNavigator. Winding through twisty, narrow mountain roads, there was ample opportunity to gauge bothvehicles' reactions. Hands down, the Navigator came out on top. The other $50,000-plus SUV lacked afirm grip on the road, especially noticeable around tight corners, and its steering was sloppycompared to that of the Navigator.

The Lincoln's independent-SLA front suspension uses monotubedampers, air springs, and a stabilizer bar. According to Lincoln, replacing coil springs on 4 3 2models and torsion bars on 4 34 models with air springs improves front-wheel recession and cuts impactharshness. Each air spring has a separate load path from the shock absorber, cutting loads on the topmount and further isolating impacts from rough roads. The front-stabilizer bar has "grippy" bushingsfor responsive and precise steering. They consist of a flat area forged into the stabilizer bar at itsmounting points that matches an oval-shaped bushing. This prevents the stabilizer bar from freelytwisting in its bushing under load, building up forces quickly for more linear steering responses.Monotube-shock absorbers respond more quickly to small changes in amplitude and velocity than thepreviously used twin-tube dampers. The better response is due to larger damping pistons. Largerpistons are possible because the shock absorbers' hydraulic fluid is stored in separate reservoirsrather than in the shocks.

An independent-rear suspension, echoing that found on its cousin, theFord Expedition, uses cast-aluminum upper and lower-control arms, and a stabilizer bar with grippybushings. A rubber-isolated torque arm links the differential to the frame. The axle halfshafts passthrough elliptical portholes in the frame, allowing 9.4 in. of wheel travel. Unsprung mass is cut by104 lb on 4 3 4 versions and 100 lb on 4 3 2s, compared to the solid axle. The IRS also boosts lateralstiffness for good steering tracking and responsiveness. Also, four-corner load-leveling air springsimprove towing capability, as well as making it easier to enter or exit the vehicle.

According toLincoln engineers, the rack-and-pinion steering has twice the torsional stiffness of the previousrecirculating-ball design, 29% less operating friction, and weighs about 22 lb less. Steering istight, but not too restrictive, and low-speed maneuverability is excellent. For example, parking theNavigator in a crowded shopping-center lot proved to be as easy as maneuvering a midsize sedan.

Optional ControlTrac four-wheel drive can be paired with the AdvanceTrac traction and stabilitysystem (also optional equipment). AdvanceTrac monitors wheel speed at each corner and uses ABS andengine management to control spin. This lets torque transfer front and back as well as side-to-sidewithout heavy locking differentials. Vehicles without AdvanceTrac have limited-slip reardifferentials. Components in the transfer case are balanced during assembly to cut noise andvibration, and clutch activation has been recalibrated for faster, smoother engagement. Also, thehousing is magnesium instead of aluminum, shaving off 11 lb.

The Navigator is powered by a5.4-liter DOHC V8 that provides 300 hp at 5,000 rpm and 355 lb-ft of torque at 2,750 rpm. Thepowerplant has an iron block, aluminum heads, and four valves per cylinder. An electronicallycontrolled four-speed automatic transmission adjusts its shift points depending on throttle position,engine vacuum, and load for smooth, undetectable shifting.

Other features worth mentioning includepower running boards and an extended rear park-assist system. When opening a door, the running boardsextend 4 in. from the rocker panel and 3 in. toward the rear, and automatically retract when the doorcloses. If the vehicle is moving or parked with all doors closed, the boards nest against the rockerpanel. All electronics and bearings are sealed against water. A mud flap prevents snow and mud fromaccumulating, and the track is self-cleaning.

The extended rear park-assist considers vehicle speedas well as distance. When reversing, it gauges how quickly the vehicle is approaching an object andadjusts its tone to the time remaining until contact occurs. The warning beep becomes a continuoustone when objects are within 8 in. The system uses a combination of two ultrasonic and radar sensorswith a range of up to 20 ft. Also, it can be turned off when towing.

Fuel economy ratings are notgreat, which comes as no surprise, at 12-mpg city/17 highway on 4 3 2 models, and 12-mpg city/16highway on 4 3 4s. The Navigator comes in three Series: Luxury, Premium, and Ultimate. Pricing startsat $48,775 for the Luxury, $50,025 for the Premium, and tops out at $54,950 for the Ultimate.